Reflex camera having reflecting finder system



June 27, 1950 J. A. HAr-:sELER 2,512,772

REFLEX CAMERA HAVING REFLECTING FINDER SYSTEM Filed Oct. 30. 1945INVENTOR BY WAW`NMWM Z0 l/l/l//I/- ATT O R N EYS Patented June 27, 1950UNITED STATES; PATENT OFFICE.

REFLEX CAMERA HAVING REFLECTING FINDER SYSTEM John A. Haeseler,Woodbridge, Conn.

Application October 30, 1945, Serial No. 625,655

'thisv invention relates to miniature cameras and: more' particularly tofinder systems of such cameras.

It is an object of the invention to provide an improved finder systemfor reflex type cameras whiclrwill also serve as a means for focusingthe cameras. With this invention the camera is held at eye level and theimage is seen through an eyepiece with the subject upright and the rightand left sides of the field correct.

The invention obtains these results with a compact system of reiiectors,which. at the same time that the reflectors turn the image and transposethe sides, produces sufficient total length of light travel sothat aneyepiece can be used which will cover the entire area of` the groundglass, and also produce good magnification. The image seen upright andwith correct sides for vertical as wellt as horizontal pictures. Inaddition to the regular camera lens the system employs one ormore lensesthat make it practical to incorporate a 4finder system of this characterinto a miniature camera.

One feature of the invention relates to a combination of opticalvelements that permits the finder system to be contained in a minimumsize of camera casing, and to a positioning of the systembelou7 the lensmount of the camera. Another feature relates to the location of theeyepiece of the finder system. at the back and in an intermediateposition between the ends of the casing By virtue of this feature theusers nose does not the eyepiece of the finder system from being broughtclose to the eye because the camera is held so that the eyepiece is atthe bottom for taking horizontal pictures and at the side for takingvertical pictures.

In order to obtain a camera casing that has a minimum front-to-backdimension, the preferred embodiment of this invention has a slidingframe correlated with the lens mount for moving parts of the structureinto a more compact relation when not in use.

'Other objects, features and advantages of the invention will appear orbe pointed out as the description proceeds.

In the drawing, forming a part hereof, in which like referencecharacters indicate corresponding parts in all the views,

Figure 1 is a diagrammatic, vertical sectional View taken through acamera embodying this invention, the section being taken along the lineI-I of Figure 2.

Figure 2 is a diagrammatic sectional view, on the line 2 2 of Figure l,but partly broken away an opening in a film gate 3D.

to show parts of the underlying finder structure in section.

Figure 3 is a diagrammatic sectional view taken on the line 3 3 ofFigure 1.

The camera shown in the drawing includes a casing I0 having guidepartitions II for guiding a sliding front I2. In the upper portion ofthe siiding front I2 there is a lens mount I5 (Figure 3) and a lensassembly that includes a barrel I6 which moves back and forth in thelens mount for focusing the camera. The structure` isshowndiagrammatically, but it will be understood that any suitableapparatus for moving the lens back and forth can be used.

The lower portion of the sliding front I2 is divided off from the upperportion by an opaque partition I8. A prism 2| is permanently attached tothe sliding front l2 below the partition I8 with the dihedral angle atthe front of the prism disposed with its vertex at an angle to the planeof the ground glass 25.

Behind the lens mount I5 there is a mirror 23 for refiecting light froma lens 24, located in the barrel I6, down against a ground glass 25. The

mirror 23 is supported by a hinged connection 26 about which the mirroris movable into the dotted line position 23 so that light from thecamera lens 24 can be thrown on a lm 28 through The film is held againstthe back of the film gate 30 by a pressure plate 32 in accordance withconventional practice. Before the sliding front I2 is pushed back intothe dotted line position I2' to collapse the rcamera for compactness incarrying the mirfror 23 is swung up into a position directly in front ofthe :film gate 30.

The camera is designed for use -with motion picture film, preferably ofthe 35 millimeter size. At one side of the camera there is a magazine 35in which the film 23 is contained for loading, and the film is woundfrom the magazine 35 to a spool 36. The length of film moved after eachexposure is determined by a sprocket 38 having teeth that engage withthe upper rovi7 of sprocket openings 3S. Apparatus for turning the spool36 and sprocket 38 to wind the film is contained within a housing 42(Figure 1) in Jthe upper part of the casing I0. The construction of thisapparatus and its controls are not illustrated in the drawing since itsdisclosure is not necessary for a complete understanding of thisinvention.

The finder apparatus of this invention is located in the chamber 25J andincludes a reflector located below the ground glass 25 and disposed atsuch an angle that it reflects the light beam from the ground glass 25forward to the prism 2l. From the prism the image is reflected to aneyepiece 4B in the back of the camera casing lil. The prism 2I hasreflecting faces at right angles to one another and it is in position toserve as a roof reflector, that is, each of the reflecting surfacesreects light to the other reflecting surface for reversing the sides ofthe image and this reversal counteracts the reversal of sides caused bythe lens 24 and reector 23 in producing the image on the ground glass25. The reversal of the sides of the image is illustrated by the lightrays 45 and 46 which represent rays from the left and right sides,respectively, of the ground glass, that pass to the prism 2 I, acrossfrom one side to the other of the prism, and then back to the eyepieceas indicated by the directions of the arrow heads along the rays.

The eyepiece 4l includes a lens 48 that makes it possible for the userof the camera, to focus his eye on the reflected image of the groundglass 25 even though the total distance from the ground glass 25 to theeyepiece 41, by Way of the reflected light beam, 'is too short for thenormal human eye to focus. At the same time the eyepiece gives goodmagnification to enable the -focusing of the image from the lens 24 onthe ground glass 25. The finder `assembly has the upper end of the prismat lsubstantially the level of the ground glass and the reiiector 44extending above the bottom level of the prism and up to the bottom levelof the eyepiece so as to make the finder structure compact and suitablefor use in a miniature camera.

When the camera is not in use, the sliding front I2 is pushed back intothe dotted line position indicated by the reference character I2' so asto reduce the overall thickness of the camera. The reector M folds downinto the dotted line position sd' in order to provide clearance for theprism ZI when the sliding front isin retracted position.

The location of the eyepiece 4l at the lower part of the casing I2 makesit possible for the user of the camera to bring the eyepiece close tothe eye with less interference by the nose than if the eyepiece werelocated at the top of the camera, but it will be understood that theterms top and bottom as used in this description and in the claims, arerelative, and that the camera can be used with the structure turned inany position. The casing can be conveniently used for taking verticalpictures by changing the position. of the camera through an angle of 90degrees as viewed in Figure 1, and when taking such vertical picturesthe eyepiece 41 is conveniently located for eye level focusing Withouthaving the camera casing strike the users nose. This .is true whetherthe eyepiece is held either to the right or the left eye.

The preferred embodiment of the invention has 4been described, withreference to the diagrammatic illustrations in the drawing, but changesand modications can be made, and some features of the invention can beused without others within the definition of the invention as set forthin the claims.

I claim as my invention:

1. A miniature camera comprising a casing having a relatively fixedportion, and a movable center portion that can be extended out beyondthe front of the xed portion of the casing on both sides of the centerand that telescopes into the xed portion to collapse the camera when notin use, a lens mount at the front of the mov- 4 able portion of thecasing, a chamber in the movable portion of the casing immediately belowthe lens mount, a nder system comprising a movable reflector behind thelens, a ground glass below the reflector and on which an image isfocused on an illuminated eld of the ground glass, another reiiectorbelow the ground glass for reiecting light from the illuminated eld ofthe ground glass forwardly and slightly upwardly, a third reector in thechamber and on the movable portion of the casing and disposed below theground glass and ahead of the forward edge of the illuminated iield ofthe ground glass when the movable portion of the casing is in `anextended position to reect light rearwardly and in a directionsubstantially parallel to the plane of the ground glass, and an eyepieceopening through the back of the fixed portion of the camera casing inposition to receive the light beam from the third reflector.

2. A reflex camera including a lens, a casing, a ground glass, areflector for reflecting light rays from the lens to the ground glass,and finder apparatus for viewing the image on the ground glass, saidfinder apparatus `comprising a first reector within and connected to thecamera casing below the ground glass and in position for directing lightrays from the ground glass forward, a second reiiector having tworeflecting surfaces at an angle to one another and disposed below theground glass and in front of the rst reflector in position to reect thelight rays from the first reflector and to reverse the sides of theground-glass image, an eyepiece opening through and attached to the backof the camera casing and to which the ground-glass image is reflected bysaid second reiiector, and 2, support that holds the second reflector ina position between the ground glass and the first reflector when thender is not in use, said support comprising a movable portion of thecasing that is movable toward and from the back of the camera far enoughto carry the second reector to a position ahead of the forward edge ofthe illuminated field of the ground glass, said movable portion of thecasing enclosing a chamber in which the reiiectors of the nder apparatusare housed and separated from the space within the casing above theground glass.

3. A camera comprising a main casing and a sliding front that telescopesinto the main casing to produce a more compact structure when the camerais not in use, a lens carried by the sliding front, a film gate locatedbehind the lens and in the main casing, a movable reflector be-` tweenthe lens and the nlm gate and adapted to occupy a position at an angleto the optical axis of the lens, a ground glass on which an image isfocused by light transmitted through the lens and reflected by saidmovable reector, partitions dividing the camera casing and slidlingfront to form a lnder-system chamber on the side of the ground glassopposite said movable reector, a first reflector located below theground glass and at `an angle to the plane ofv the ground glass fordirecting light rays from the ground glass forward with an upwardcomponent, a second reflector secured to the sliding front in the pathof the reflected light rays from the rst finder reector, said secondreflector including two reflecting surfaces at right angles to oneanother and with their line of intersection in substantially the samevertical plane with the optical axis of the lens, the reflectingsurfaces of said second reector being disposed at angles;

that change the sides of the image and direct the reflected light raysfrom the rst reflector rearwardly to an eyepiece opening through theback of the camera casing.

4. A camera comprising a main Icasing and a sliding front thattelescopes into the main casing to produce a more compact structure whenthe camera is not in use, a lens carried by the sliding front, a filmgate located behind the lens and in the main casing, a movable reectorbetween the lens and the film gate and adapted to occupy a position atan angle to the optical axis of the lens, a ground glass on which animage is focused by light transmitted through the lens and reflected bysaid movable reflector, a rst reflector located below the ground glassand at an angle to the plane of the ground glass for directing lightrays from the ground glass for- Ward with an upward component, a secondreector secured to the sliding front in the path of the reflected lightrays from the first finder reflector, said second reflector includingtwo reflecting surfaces at right angles to one another and with theirline of intersection in substantially the same vertical plane with theoptical axis of the lens, the refiecting surfaces of said secondreflector being disposed at angles that change the sides of the imageand direct the reflected light rays from the rs't reflector rearwardlyto an eyepiece opening through the back of the camera casing.

JOHN A. HAESELER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 741,102 Borsum Oct. 13, 19032,252,640 Nuchterlein Aug. 12, 1941 2,310,273 Bancroft Feb. 9, 19432,323,005 Bertele June 29, 1943 FOREIGN PATENTS Number Country Date39,991 France Dec. 28, 1931 (Addition to 678,148)

556,783 Germany Jan. 28, 1933 879,245 France Nov. 10, 1942 884,054France Apr. 12, 1943 OTHER REFERENCES Ser. No. 304,702, Kuppenbender (A.P. C.), published May 4, 1943.

